With regard to the performance data of OLEDs, further improvements are still required, especially with regard to broad commercial use, for example in display devices or as light sources. Of particular significance in this connection are the lifetime, the efficiency and the operating voltage of the OLEDs, and the color values achieved. Especially in the case of blue-emitting OLEDs, there is potential for improvement with regard to the lifetime of the devices. In addition, it is desirable that the compounds, for use as functional materials in electronic devices, have a high thermal stability and a high glass transition temperature and can be sublimed without decomposition.
Document CN 102030701A describes compounds having an indeno[1,2,3-jk]fluorene skeleton. Document US 2006/0094859 A1 describes polymers having multiply bridged biphenyl units.